Double Cylinder Function: The deadbolt is thrown and retracted by a key from either side. As you will not be able to unlock this from the inside without a key, please check your local fire code to ensure this is allowed before purchasing.All Emtek items are made to order.Emtek's double cylinder deadbolts use traditional American locks complete with a variety of trim styles, handcrafted from authentic materials. The deadbolt is operated by a key from both the exterior and the interior. Uncompromisingly rugged and beautifully crafted, these locks are suitable for the very finest homes.The Brass Modern Collection's latches are heavy-duty die cast construction, with strong internal springs, solid brass nose bolts, and sintered metal cams. A plastic bushing located in the joint between the handle and the rosette ensures a friction-free wear surface, preventing metal from bearing on metal and providing smooth, long-lasting operation. Handles are positively connected to rosettes with a permanent clip. Each has a set screw which eliminates "handle wobble" when tightened. Emtek's threaded tubes are machined brass to ensure good threads and prevent corrosion.Emtek is dedicated to bringing interesting, well made hardware back into American homes. Emtek's mission is to satisfy the higher expectations of today's homeowners with regard to door locks. They strive to provide a broad and interesting range of products that consumers can use as elements of decor, and not just as a way to latch a door.